Sequestered and Synthesized Chemical Defenses in the Poison Frog Melanophryniscus moreirae

2015 ◽  
Vol 41 (5) ◽  
pp. 505-512 ◽  
Author(s):  
Adriana M. Jeckel ◽  
Taran Grant ◽  
Ralph A. Saporito
Keyword(s):  
Chemical Defenses ◽  
Poison Frog

scholarly journals Molecular physiology of chemical defenses in a poison frog

2019 ◽  
Vol 222 (12) ◽  
pp. jeb204149 ◽  
Author(s):  
Stephanie N. Caty ◽  
Aurora Alvarez-Buylla ◽  
Gary D. Byrd ◽  
Charles Vidoudez ◽  
Alexandre B. Roland ◽  
...  
Keyword(s):  
Chemical Defenses ◽  
Molecular Physiology ◽  
Poison Frog

scholarly journals Ant and mite diversity drives toxin variation in the Little Devil poison frog

2015 ◽  
Author(s):  
Jenna R McGugan ◽  
Gary D Byrd ◽  
Alexandre B Roland ◽  
Stephanie N Caty ◽  
Nisha Kabir ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Frog Skin ◽  
Stomach Contents ◽  
Principal Component ◽  
Chemical Defenses ◽  
Chemical Diversity ◽  
Gas Chromatography Mass Spectrometry ◽  
Poison Frog ◽  
Chromatography Mass Spectrometry ◽  
Chemical Profiles

Poison frogs sequester chemical defenses from arthropod prey, although the details of how arthropod diversity contributes to variation in poison frog toxins remains unclear. We characterized skin alkaloid profiles in the Little Devil frog, Oophaga sylvatica (Dendrobatidae), across three populations in northwestern Ecuador. Using gas chromatography mass spectrometry, we identified histrionicotoxins, 3,5- and 5,8-disubstituted indolizidines, decahydroquinolines, and lehmizidines as the primary alkaloid toxins in these O. sylvatica populations. Frog skin alkaloid composition varied along a latitudinal gradient across populations in a principal component analysis. We also characterized diversity in arthropods isolated from frog stomach contents and confirmed O. sylvatica specialize on ants and mites. To test the hypothesis that poison frog toxin diversity reflects species and chemical diversity in arthropod prey, we (1) used liquid chromatography mass spectrometry to chemically profile consumed ants and mites, and (2) used sequencing of cytochrome oxidase 1 to identify individual prey specimens. We show that chemical profiles of consumed ants and mites cluster by frog population, suggesting different frog populations have access to chemically distinct prey. We identified 45 ants and 9 mites isolated from frog stomachs, finding several undescribed species. Finally, by comparing chemical profiles of frog skin and isolated prey items, we were able to trace the arthropod source of four poison frog alkaloids, including 3,5- and 5,8-disubstituted indolizidines and a lehmizidine alkaloid. Together, our data shows the diversity of alkaloid toxins found in O. sylvatica can be traced to chemical diversity in arthropod prey.

scholarly journals Rapid toxin sequestration modifies poison frog physiology

2021 ◽  
pp. jeb.230342
Author(s):  
Lauren A. O'Connell ◽  
Jeremy D. O'Connell ◽  
Joao A. Paulo ◽  
Sunia A. Trauger ◽  
Steven P. Gygi ◽  
...  
Keyword(s):  
Small Molecule ◽  
Chemical Defenses ◽  
Protein Abundance ◽  
Poison Frog ◽  
Poison Frogs ◽  
Toxin Binding ◽  
Physiological Adaptations ◽  
Molecule Transport ◽  
Protein Classes ◽  
Small Molecule Transport

Poison frogs sequester chemical defenses from their diet of leaf litter arthropods for defense against predation. Little is known about the physiological adaptations that confer this unusual bioaccumulation ability. We conducted an alkaloid-feeding experiment with the Diablito poison frog (Oophaga sylvatica) to determine how quickly alkaloids are accumulated and how toxins modify frog physiology using quantitative proteomics. Diablito frogs rapidly accumulated the alkaloid decahydroquinoline within four days, and dietary alkaloid exposure altered protein abundance in the intestines, liver, and skin. Many proteins that increased in abundance with decahydroquinoline accumulation are plasma glycoproteins, including the complement system and the toxin-binding protein saxiphilin. Other protein classes that change in abundance with decahydroquinoline accumulation are membrane proteins involved in small molecule transport and metabolism. Overall, this work shows poison frogs can rapidly accumulate alkaloids, which alter carrier protein abundance, initiate an immune response, and alter small molecule transport and metabolism dynamics across tissues.

scholarly journals Land use impacts poison frog chemical defenses through changes in leaf litter ant communities

2019 ◽  
Author(s):  
Nora A. Moskowitz ◽  
Barbara Dorritie ◽  
Tammy Fay ◽  
Olivia C. Nieves ◽  
Charles Vidoudez ◽  
...  
Keyword(s):  
Land Use ◽  
Leaf Litter ◽  
Secondary Forest ◽  
Land Use Changes ◽  
Chemical Defenses ◽  
Trophic Levels ◽  
High School Science ◽  
Land Use Impacts ◽  
Ant Communities ◽  
Poison Frog

AbstractMuch of the world’s biodiversity is held within tropical rainforests, which are increasingly fragmented by agricultural practices. In these threatened landscapes, there are many organisms that acquire chemical defenses from their diet and are therefore intimately connected with their local food webs. Poison frogs (Family Dendrobatidae) are one such example, as they acquire alkaloid-based chemical defenses from their diet of leaf litter ants and mites. It is currently unknown how habitat fragmentation impacts chemical defense across trophic levels, from arthropods to frogs. We examined the chemical defenses and diets of the Diablito poison frog (Oophaga sylvatica), and the diversity of their leaf litter ant communities in secondary forest and reclaimed cattle pasture. Notably, this research was performed in collaboration with two high school science classrooms. We found that the leaf litter of forest and pasture frog habitats differed significantly in ant community structure. We also found that forest and pasture frogs differed significantly in diet and alkaloid profiles, where forest frogs contained more of specific alkaloids and ate more ants in both number and volume. Finally, ant species composition of frog diets resembled the surrounding leaf litter, but diets were less variable. This suggests that frogs tend to consume particular ant species within each habitat. To better understand how ants contribute to the alkaloid chemical profiles of frogs, we chemically profiled several ant species and found some alkaloids to be common across many ant species while others are restricted to a few species. At least one alkaloid (223H) found in ants from disturbed sites was also found in skins from pasture. Our experiments are the first to link anthropogenic land use changes to dendrobatid poison frog chemical defenses through variation in leaf litter communities, which has implications for conservation management of these threatened amphibians.

Chemical defenses shift with the seasonal vertical migration of a Panamanian poison frog

Biotropica ◽  
2020 ◽  
Author(s):  
Edmund W. Basham ◽  
Ralph A. Saporito ◽  
Macario González‐Pinzón ◽  
Angel Romero‐Marcucci ◽  
Brett R. Scheffers
Keyword(s):  
Vertical Migration ◽  
Chemical Defenses ◽  
Poison Frog

scholarly journals Seasonal Changes in Diet and Toxicity in the Climbing Mantella Frog (Mantella Laevigata)

2018 ◽  
Author(s):  
Nora A. Moskowitz ◽  
Alexandre B. Roland ◽  
Eva K. Fischer ◽  
Ndimbintsoa Ranaivorazo ◽  
Charles Vidoudez ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Environmental Variation ◽  
Chemical Defenses ◽  
Gas Chromatography Mass Spectrometry ◽  
Insect Larvae ◽  
Wet Season ◽  
Poison Frog ◽  
Poison Frogs ◽  
Dry Seasons ◽  
Wet And Dry Seasons

AbstractPoison frogs acquire chemical defenses from the environment for protection against potential predators. These defensive chemicals are lipophilic alkaloid toxins that are sequestered by poison frogs from dietary arthropods and stored in skin glands. Despite decades of research focusing on identifying poison frog toxins, we know relatively little about how environmental variation and subsequent arthropod availability impacts toxicity in poison frogs. We investigated how seasonal environmental variation influences poison frog toxin profiles through changes in the diet of the Climbing Mantella (Mantella laevigata). We collected M. laevigata females on the Nosy Mangabe island reserve in Madagascar during the wet and dry seasons and tested the hypothesis that seasonal differences in rainfall is associated with changes in the diet and skin toxin profiles of M. laevigata. The arthropod diet of each frog was characterized into five groups (i.e. ants, termites, mites, insect larvae, or ‘other’) using visual identification and cytochrome oxidase 1 DNA barcoding. We found that frog diet differed between the wet and dry seasons, where frogs had a more diverse diet in the wet season and consumed a higher percentage of ants in the dry season. To determine if seasonality was associated with variation in frog defensive chemical composition, we used gas chromatography / mass spectrometry to quantify toxins from individual skin samples. Although the assortment of identified toxins was similar across seasons, we detected significant differences in the abundance of certain alkaloids, which we hypothesize reflects seasonal variation in the diet of M. laevigata. We suggest that these variations could originate from seasonal changes in either arthropod leaf litter composition or changes in frog behavioral patterns. Although additional studies are needed to understand the consequences of long-term environmental shifts, this work suggests that toxin profiles are relatively robust against short-term environmental perturbations.

scholarly journals Land use impacts poison frog chemical defenses through changes in leaf litter ant communities

2020 ◽  
Vol 6 (1) ◽  
pp. lxxv-lxxxvii ◽  
Author(s):  
Nora A. Moskowitz ◽  
Barbara Dorritie ◽  
Tammy Fay ◽  
Olivia C. Nieves ◽  
Charles Vidoudez ◽  
...  
Keyword(s):  
Land Use ◽  
Leaf Litter ◽  
Chemical Defenses ◽  
Land Use Impacts ◽  
Ant Communities ◽  
Poison Frog

scholarly journals Rapid toxin sequestration modifies poison frog physiology

2020 ◽  
Author(s):  
Lauren A. O’Connell ◽  
Jeremy D. O’Connell ◽  
Joao A. Paulo ◽  
Sunia A. Trauger ◽  
Steven P. Gygi ◽  
...  
Keyword(s):  
Small Molecule ◽  
Chemical Defenses ◽  
Protein Abundance ◽  
Poison Frog ◽  
Poison Frogs ◽  
Toxin Binding ◽  
Molecule Transport ◽  
Summary Statement ◽  
Protein Classes ◽  
Small Molecule Transport

AbstractPoison frogs sequester chemical defenses from their diet of leaf litter arthropods for defense against predation. Little is known about the physiological adaptations that confer this unusual bioaccumulation ability. We conducted an alkaloid-feeding experiment with the Diablito poison frog (Oophaga sylvatica) to determine how quickly alkaloids are accumulated and how toxins modify frog physiology using quantitative proteomics. Diablito frogs rapidly accumulated the alkaloid decahydroquinoline within four days, and dietary alkaloid exposure altered protein abundance in the intestines, liver, and skin. Many proteins that increased in abundance with decahydroquinoline accumulation are plasma glycoproteins, including the complement system and the toxin-binding protein saxiphilin. Other protein classes that change in abundance with decahydroquinoline accumulation are membrane proteins involved in small molecule transport and metabolism. Overall, this work shows poison frogs can rapidly accumulate alkaloids, which alter carrier protein abundance, initiate an immune response, and alter small molecule transport and metabolism dynamics across tissues.Summary StatementPoison frogs rapidly accumulate toxins, which changes abundance of proteins involved in the immune system and small molecule binding and metabolism across tissues.

scholarly journals The relationship between poison frog chemical defenses and age, body size, and sex

2015 ◽  
Vol 12 (1) ◽  
Author(s):  
Adriana M. Jeckel ◽  
Ralph A. Saporito ◽  
Taran Grant
Keyword(s):  
Body Size ◽  
Chemical Defenses ◽  
Poison Frog ◽  
The Relationship

scholarly journals Ecophysiological Aspects and sxt Genes Expression Underlying Induced Chemical Defense in STX-Producing Raphidiopsis raciborskii (Cyanobacteria) against the Zooplankter Daphnia gessneri

Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 406
Author(s):  
Mauro C. P. Vilar ◽  
Thiago F. C. P. Rodrigues ◽  
Luan O. Silva ◽  
Ana Beatriz F. Pacheco ◽  
Aloysio S. Ferrão-Filho ◽  
...  
Keyword(s):  
Induced Defense ◽  
Toxin Production ◽  
Grazing Pressure ◽  
Chemical Defenses ◽  
Widespread Occurrence ◽  
Genes Expression ◽  
Freshwater Bodies ◽  
Predator Response ◽  
Aquatic Food ◽  
Shed Light

Cyanobacteria stand out among phytoplankton when they form massive blooms and produce toxins. Because cyanotoxin genes date to the origin of metazoans, the hypothesis that cyanotoxins function as a defense against herbivory is still debated. Although their primary cellular function might vary, these metabolites could have evolved as an anti-predator response. Here we evaluated the physiological and molecular responses of a saxitoxin-producing Raphidiopsis raciborskii to infochemicals released by the grazer Daphnia gessneri. Induced chemical defenses were evidenced in R. raciborskii as a significant increase in the transcription level of sxt genes, followed by an increase in saxitoxin content when exposed to predator cues. Moreover, cyanobacterial growth decreased, and no significant effects on photosynthesis or morphology were observed. Overall, the induced defense response was accompanied by a trade-off between toxin production and growth. These results shed light on the mechanisms underlying zooplankton–cyanobacteria interactions in aquatic food webs. The widespread occurrence of the cyanobacterium R. raciborskii in freshwater bodies has been attributed to its phenotypic plasticity. Assessing the potential of this species to thrive over interaction filters such as zooplankton grazing pressure can enhance our understanding of its adaptive success.

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